<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
		.container {
			width: 100%;
			height: 100px;
			display: flex;
			justify-content: space-around;
		}

		.item1 {
			width: 100px;
			background-color: red;
		}

		.item2 {
			background-color: orange;
			flex-grow: 1;
		}

		.item3 {
			width: 100px;
			background-color: pink;
		}
	</style>
</head>
<body>
	<div class="container">
		<div class="item1">1</div>
		<div class="item2">2</div>
		<div class="item3">3</div>
	</div>
</body>
</html>